465 lines
13 KiB
ArmAsm
465 lines
13 KiB
ArmAsm
/*
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* Implement fast CRC32C with PCLMULQDQ instructions. (x86_64)
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*
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* The white papers on CRC32C calculations with PCLMULQDQ instruction can be
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* downloaded from:
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* http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/crc-iscsi-polynomial-crc32-instruction-paper.pdf
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* http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/fast-crc-computation-paper.pdf
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*
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* Copyright (C) 2012 Intel Corporation.
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*
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* Authors:
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* Wajdi Feghali <wajdi.k.feghali@intel.com>
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* James Guilford <james.guilford@intel.com>
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* David Cote <david.m.cote@intel.com>
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* Tim Chen <tim.c.chen@linux.intel.com>
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the
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* OpenIB.org BSD license below:
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*
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* Redistribution and use in source and binary forms, with or
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* without modification, are permitted provided that the following
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* conditions are met:
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*
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* - Redistributions of source code must retain the above
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* copyright notice, this list of conditions and the following
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* disclaimer.
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*
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* - Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include <asm/inst.h>
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#include <linux/linkage.h>
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#include <asm/nospec-branch.h>
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## ISCSI CRC 32 Implementation with crc32 and pclmulqdq Instruction
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.macro LABEL prefix n
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\prefix\n\():
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.endm
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.macro JMPTBL_ENTRY i
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.word crc_\i - crc_array
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.endm
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.macro JNC_LESS_THAN j
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jnc less_than_\j
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.endm
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# Define threshold where buffers are considered "small" and routed to more
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# efficient "by-1" code. This "by-1" code only handles up to 255 bytes, so
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# SMALL_SIZE can be no larger than 255.
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#define SMALL_SIZE 200
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.if (SMALL_SIZE > 255)
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.error "SMALL_ SIZE must be < 256"
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.endif
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# unsigned int crc_pcl(u8 *buffer, int len, unsigned int crc_init);
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.text
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ENTRY(crc_pcl)
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#define bufp %rdi
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#define bufp_dw %edi
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#define bufp_w %di
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#define bufp_b %dil
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#define bufptmp %rcx
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#define block_0 %rcx
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#define block_1 %rdx
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#define block_2 %r11
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#define len %rsi
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#define len_dw %esi
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#define len_w %si
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#define len_b %sil
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#define crc_init_arg %rdx
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#define tmp %rbx
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#define crc_init %r8
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#define crc_init_dw %r8d
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#define crc1 %r9
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#define crc2 %r10
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pushq %rbx
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pushq %rdi
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pushq %rsi
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## Move crc_init for Linux to a different
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mov crc_init_arg, crc_init
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################################################################
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## 1) ALIGN:
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################################################################
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mov bufp, bufptmp # rdi = *buf
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neg bufp
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and $7, bufp # calculate the unalignment amount of
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# the address
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je proc_block # Skip if aligned
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## If len is less than 8 and we're unaligned, we need to jump
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## to special code to avoid reading beyond the end of the buffer
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cmp $8, len
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jae do_align
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# less_than_8 expects length in upper 3 bits of len_dw
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# less_than_8_post_shl1 expects length = carryflag * 8 + len_dw[31:30]
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shl $32-3+1, len_dw
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jmp less_than_8_post_shl1
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do_align:
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#### Calculate CRC of unaligned bytes of the buffer (if any)
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movq (bufptmp), tmp # load a quadward from the buffer
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add bufp, bufptmp # align buffer pointer for quadword
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# processing
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sub bufp, len # update buffer length
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align_loop:
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crc32b %bl, crc_init_dw # compute crc32 of 1-byte
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shr $8, tmp # get next byte
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dec bufp
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jne align_loop
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proc_block:
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################################################################
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## 2) PROCESS BLOCKS:
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################################################################
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## compute num of bytes to be processed
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movq len, tmp # save num bytes in tmp
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cmpq $128*24, len
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jae full_block
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continue_block:
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cmpq $SMALL_SIZE, len
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jb small
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## len < 128*24
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movq $2731, %rax # 2731 = ceil(2^16 / 24)
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mul len_dw
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shrq $16, %rax
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## eax contains floor(bytes / 24) = num 24-byte chunks to do
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## process rax 24-byte chunks (128 >= rax >= 0)
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## compute end address of each block
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## block 0 (base addr + RAX * 8)
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## block 1 (base addr + RAX * 16)
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## block 2 (base addr + RAX * 24)
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lea (bufptmp, %rax, 8), block_0
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lea (block_0, %rax, 8), block_1
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lea (block_1, %rax, 8), block_2
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xor crc1, crc1
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xor crc2, crc2
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## branch into array
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lea jump_table(%rip), bufp
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movzwq (bufp, %rax, 2), len
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lea crc_array(%rip), bufp
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lea (bufp, len, 1), bufp
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JMP_NOSPEC bufp
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################################################################
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## 2a) PROCESS FULL BLOCKS:
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################################################################
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full_block:
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movl $128,%eax
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lea 128*8*2(block_0), block_1
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lea 128*8*3(block_0), block_2
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add $128*8*1, block_0
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xor crc1,crc1
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xor crc2,crc2
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# Fall thruogh into top of crc array (crc_128)
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################################################################
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## 3) CRC Array:
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################################################################
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crc_array:
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i=128
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.rept 128-1
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.altmacro
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LABEL crc_ %i
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.noaltmacro
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crc32q -i*8(block_0), crc_init
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crc32q -i*8(block_1), crc1
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crc32q -i*8(block_2), crc2
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i=(i-1)
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.endr
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.altmacro
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LABEL crc_ %i
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.noaltmacro
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crc32q -i*8(block_0), crc_init
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crc32q -i*8(block_1), crc1
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# SKIP crc32 -i*8(block_2), crc2 ; Don't do this one yet
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mov block_2, block_0
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################################################################
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## 4) Combine three results:
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################################################################
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lea (K_table-8)(%rip), bufp # first entry is for idx 1
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shlq $3, %rax # rax *= 8
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pmovzxdq (bufp,%rax), %xmm0 # 2 consts: K1:K2
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leal (%eax,%eax,2), %eax # rax *= 3 (total *24)
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subq %rax, tmp # tmp -= rax*24
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movq crc_init, %xmm1 # CRC for block 1
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PCLMULQDQ 0x00,%xmm0,%xmm1 # Multiply by K2
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movq crc1, %xmm2 # CRC for block 2
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PCLMULQDQ 0x10, %xmm0, %xmm2 # Multiply by K1
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pxor %xmm2,%xmm1
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movq %xmm1, %rax
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xor -i*8(block_2), %rax
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mov crc2, crc_init
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crc32 %rax, crc_init
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################################################################
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## 5) Check for end:
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################################################################
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LABEL crc_ 0
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mov tmp, len
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cmp $128*24, tmp
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jae full_block
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cmp $24, tmp
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jae continue_block
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less_than_24:
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shl $32-4, len_dw # less_than_16 expects length
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# in upper 4 bits of len_dw
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jnc less_than_16
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crc32q (bufptmp), crc_init
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crc32q 8(bufptmp), crc_init
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jz do_return
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add $16, bufptmp
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# len is less than 8 if we got here
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# less_than_8 expects length in upper 3 bits of len_dw
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# less_than_8_post_shl1 expects length = carryflag * 8 + len_dw[31:30]
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shl $2, len_dw
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jmp less_than_8_post_shl1
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#######################################################################
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## 6) LESS THAN 256-bytes REMAIN AT THIS POINT (8-bits of len are full)
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#######################################################################
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small:
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shl $32-8, len_dw # Prepare len_dw for less_than_256
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j=256
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.rept 5 # j = {256, 128, 64, 32, 16}
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.altmacro
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LABEL less_than_ %j # less_than_j: Length should be in
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# upper lg(j) bits of len_dw
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j=(j/2)
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shl $1, len_dw # Get next MSB
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JNC_LESS_THAN %j
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.noaltmacro
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i=0
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.rept (j/8)
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crc32q i(bufptmp), crc_init # Compute crc32 of 8-byte data
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i=i+8
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.endr
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jz do_return # Return if remaining length is zero
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add $j, bufptmp # Advance buf
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.endr
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less_than_8: # Length should be stored in
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# upper 3 bits of len_dw
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shl $1, len_dw
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less_than_8_post_shl1:
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jnc less_than_4
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crc32l (bufptmp), crc_init_dw # CRC of 4 bytes
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jz do_return # return if remaining data is zero
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add $4, bufptmp
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less_than_4: # Length should be stored in
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# upper 2 bits of len_dw
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shl $1, len_dw
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jnc less_than_2
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crc32w (bufptmp), crc_init_dw # CRC of 2 bytes
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jz do_return # return if remaining data is zero
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add $2, bufptmp
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less_than_2: # Length should be stored in the MSB
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# of len_dw
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shl $1, len_dw
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jnc less_than_1
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crc32b (bufptmp), crc_init_dw # CRC of 1 byte
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less_than_1: # Length should be zero
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do_return:
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movq crc_init, %rax
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popq %rsi
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popq %rdi
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popq %rbx
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ret
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ENDPROC(crc_pcl)
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.section .rodata, "a", @progbits
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################################################################
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## jump table Table is 129 entries x 2 bytes each
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################################################################
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.align 4
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jump_table:
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i=0
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.rept 129
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.altmacro
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JMPTBL_ENTRY %i
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.noaltmacro
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i=i+1
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.endr
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################################################################
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## PCLMULQDQ tables
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## Table is 128 entries x 2 words (8 bytes) each
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################################################################
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.align 8
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K_table:
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.long 0x493c7d27, 0x00000001
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.long 0xba4fc28e, 0x493c7d27
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.long 0xddc0152b, 0xf20c0dfe
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.long 0x9e4addf8, 0xba4fc28e
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.long 0x39d3b296, 0x3da6d0cb
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.long 0x0715ce53, 0xddc0152b
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.long 0x47db8317, 0x1c291d04
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.long 0x0d3b6092, 0x9e4addf8
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.long 0xc96cfdc0, 0x740eef02
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.long 0x878a92a7, 0x39d3b296
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.long 0xdaece73e, 0x083a6eec
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.long 0xab7aff2a, 0x0715ce53
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.long 0x2162d385, 0xc49f4f67
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.long 0x83348832, 0x47db8317
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.long 0x299847d5, 0x2ad91c30
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.long 0xb9e02b86, 0x0d3b6092
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.long 0x18b33a4e, 0x6992cea2
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.long 0xb6dd949b, 0xc96cfdc0
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.long 0x78d9ccb7, 0x7e908048
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.long 0xbac2fd7b, 0x878a92a7
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.long 0xa60ce07b, 0x1b3d8f29
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.long 0xce7f39f4, 0xdaece73e
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.long 0x61d82e56, 0xf1d0f55e
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.long 0xd270f1a2, 0xab7aff2a
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.long 0xc619809d, 0xa87ab8a8
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.long 0x2b3cac5d, 0x2162d385
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.long 0x65863b64, 0x8462d800
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.long 0x1b03397f, 0x83348832
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.long 0xebb883bd, 0x71d111a8
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.long 0xb3e32c28, 0x299847d5
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.long 0x064f7f26, 0xffd852c6
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.long 0xdd7e3b0c, 0xb9e02b86
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.long 0xf285651c, 0xdcb17aa4
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.long 0x10746f3c, 0x18b33a4e
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.long 0xc7a68855, 0xf37c5aee
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.long 0x271d9844, 0xb6dd949b
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.long 0x8e766a0c, 0x6051d5a2
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.long 0x93a5f730, 0x78d9ccb7
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.long 0x6cb08e5c, 0x18b0d4ff
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.long 0x6b749fb2, 0xbac2fd7b
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.long 0x1393e203, 0x21f3d99c
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.long 0xcec3662e, 0xa60ce07b
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.long 0x96c515bb, 0x8f158014
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.long 0xe6fc4e6a, 0xce7f39f4
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.long 0x8227bb8a, 0xa00457f7
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.long 0xb0cd4768, 0x61d82e56
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.long 0x39c7ff35, 0x8d6d2c43
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.long 0xd7a4825c, 0xd270f1a2
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.long 0x0ab3844b, 0x00ac29cf
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.long 0x0167d312, 0xc619809d
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.long 0xf6076544, 0xe9adf796
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.long 0x26f6a60a, 0x2b3cac5d
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.long 0xa741c1bf, 0x96638b34
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.long 0x98d8d9cb, 0x65863b64
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.long 0x49c3cc9c, 0xe0e9f351
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.long 0x68bce87a, 0x1b03397f
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.long 0x57a3d037, 0x9af01f2d
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.long 0x6956fc3b, 0xebb883bd
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.long 0x42d98888, 0x2cff42cf
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.long 0x3771e98f, 0xb3e32c28
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.long 0xb42ae3d9, 0x88f25a3a
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.long 0x2178513a, 0x064f7f26
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.long 0xe0ac139e, 0x4e36f0b0
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.long 0x170076fa, 0xdd7e3b0c
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.long 0x444dd413, 0xbd6f81f8
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.long 0x6f345e45, 0xf285651c
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.long 0x41d17b64, 0x91c9bd4b
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.long 0xff0dba97, 0x10746f3c
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.long 0xa2b73df1, 0x885f087b
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.long 0xf872e54c, 0xc7a68855
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.long 0x1e41e9fc, 0x4c144932
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.long 0x86d8e4d2, 0x271d9844
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.long 0x651bd98b, 0x52148f02
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.long 0x5bb8f1bc, 0x8e766a0c
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.long 0xa90fd27a, 0xa3c6f37a
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.long 0xb3af077a, 0x93a5f730
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.long 0x4984d782, 0xd7c0557f
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.long 0xca6ef3ac, 0x6cb08e5c
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.long 0x234e0b26, 0x63ded06a
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.long 0xdd66cbbb, 0x6b749fb2
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.long 0x4597456a, 0x4d56973c
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.long 0xe9e28eb4, 0x1393e203
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.long 0x7b3ff57a, 0x9669c9df
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.long 0xc9c8b782, 0xcec3662e
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.long 0x3f70cc6f, 0xe417f38a
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.long 0x93e106a4, 0x96c515bb
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.long 0x62ec6c6d, 0x4b9e0f71
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.long 0xd813b325, 0xe6fc4e6a
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.long 0x0df04680, 0xd104b8fc
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.long 0x2342001e, 0x8227bb8a
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.long 0x0a2a8d7e, 0x5b397730
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.long 0x6d9a4957, 0xb0cd4768
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.long 0xe8b6368b, 0xe78eb416
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.long 0xd2c3ed1a, 0x39c7ff35
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.long 0x995a5724, 0x61ff0e01
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.long 0x9ef68d35, 0xd7a4825c
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.long 0x0c139b31, 0x8d96551c
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.long 0xf2271e60, 0x0ab3844b
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.long 0x0b0bf8ca, 0x0bf80dd2
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.long 0x2664fd8b, 0x0167d312
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.long 0xed64812d, 0x8821abed
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.long 0x02ee03b2, 0xf6076544
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.long 0x8604ae0f, 0x6a45d2b2
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.long 0x363bd6b3, 0x26f6a60a
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.long 0x135c83fd, 0xd8d26619
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.long 0x5fabe670, 0xa741c1bf
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.long 0x35ec3279, 0xde87806c
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.long 0x00bcf5f6, 0x98d8d9cb
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.long 0x8ae00689, 0x14338754
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.long 0x17f27698, 0x49c3cc9c
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.long 0x58ca5f00, 0x5bd2011f
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.long 0xaa7c7ad5, 0x68bce87a
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.long 0xb5cfca28, 0xdd07448e
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.long 0xded288f8, 0x57a3d037
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.long 0x59f229bc, 0xdde8f5b9
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.long 0x6d390dec, 0x6956fc3b
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.long 0x37170390, 0xa3e3e02c
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.long 0x6353c1cc, 0x42d98888
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.long 0xc4584f5c, 0xd73c7bea
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.long 0xf48642e9, 0x3771e98f
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.long 0x531377e2, 0x80ff0093
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.long 0xdd35bc8d, 0xb42ae3d9
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.long 0xb25b29f2, 0x8fe4c34d
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.long 0x9a5ede41, 0x2178513a
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.long 0xa563905d, 0xdf99fc11
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.long 0x45cddf4e, 0xe0ac139e
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.long 0xacfa3103, 0x6c23e841
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.long 0xa51b6135, 0x170076fa
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